$(document).ready(function() {
$('.m1, .m2, .m3').append('<span class="hover"></span>')
.each(function (){var $span = $('> span.hover', this).css('opacity', 0);$(this).hover(function () {$span.stop().fadeTo(500, 1);}, function () {$span.stop().fadeTo(500, 0);});});});